The End of Evolution By Means of Natural Selection

Hi, Faith.I'm honored to finally meet you(r words): I've heard so much about you. I think you've been missed here. Can you tell me the difference between your argument and the one in which humans can’t have evolved from apes because there are still apes around?When you say, established, I think you mean fixed. A fixed trait is one that is present in all individuals in a population. And, there is no rule that dictates that any trait has to become fixed in a population. Evolution can proceed just fine without any trait having ever become fixed in any population.Only in a minority of cases do we actually encounter a single allele that is clearly superior to all alternative alleles in the population. Certainly, we should expect that some alleles---maybe even most of the alleles--- should be outcompeted and gradually depleted into nothing, but there is no rule about how many alleles can persist in a population for any given amount of time. Here is a good example: in the side-blotched lizard, different males employ three different mating strategies (loyal guardian, dominating bully and sneaky cheater), all of which have been determined to be driven (at least in part) by genetics, and no one of which is sufficiently superior that it totally crowds the others out of the gene pool.Inferiority is not a death sentence. Nature is far too complex to think that any appreciable number of genes have a single best allele among the available options. Thus, we should expect a considerable measure of diversity to persist at a considerable number of loci in the genome.----- Then why is it that we actually see so much variation in genomes around the world?It is only a minority of alleles that are ever crucial in any situation, so it is only a minority of cases that result in one allele competitively eliminating all the alternatives. Tolerance of variability in any given gene is the norm in the real world, Faith: that’s the whole reason we even see alleles at all.Natural selection does not have to smite all the competitors, it just has to smite some of the competitors.Edited by Bluejay, : "this" for "your"

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Capt Stormfield. There are several different arguments that could be brought against Faith's argument as it stands. NWR hit a good one in distinguishing between genotype and phenotype, and I mentioned the "successional evolution" folly, and Paul argued the math.I think that, in general, Faith is dealing in simple, absolute principles, which really is not an appropriate paradigm for evolutionary biology.I thought about pointing out that the generational mutation rate for humans has recently been estimated at approximately 60/individual; and that this would require natural selection to be able to entirely eliminate more than 60 alleles that were already present in the population every time a new individual was born, in order for the genetic diversity in the population to actually decrease. At the time, I decided that there were easier ways of making my point, though.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith.I don’t really want to pile it on too thick, but I wanted to add one point that I don’t think has been adequately addressed so far. Forgive me for the length and the detail. After this post, I’ll stop and hopefully that will make it easier for you to keep up with the demands placed on you here. The thing you’ve neglected is time. You’ve got this Heisenberg-like problem, where you’re trying to address what’s happening in evolution right now, and you’ve neglected the fact that right now is just one tiny piece of the process.Even as selection starts acting on specific traits, mutation is still acting in the genome as well. And, while selection often takes many generations to play out to its end, the work of a mutation is done after a single cell division. Each individual will most likely contain several dozen new mutations, many of which will constitute new alleles or alter the expression patterns of existing alleles. And, some of these mutations can remain hidden in recessive alleles for a very long time: it’s very hard to entirely weed out a deleterious allele that doesn’t always express it’s deleterious effects.So, while selection is going about the business whacking 19 of your 20 alleles, organisms with those 19 alleles are still persisting for a good number of generations beyond the introduction of the champion allele, and mutating at many, many times the rate of selection for that champion. Furthermore, since there isn’t just one beneficial trait in an organism, there isn’t just one champion allele. So, organisms with those 19 alleles may also have other traits that are beneficial or superior, and can compensate for their inferiority at the locus you’re addressing, which will further reduce the rate of selection-mediated extinction of the 19 inferior alleles.The result is that we should expect a large diversity of alleles to persist for a long time, even in the presence of a superior mutant. And, extending the time of persistence extends the chance for new beneficial mutations to be associated with those inferior alleles, and the chance that some environmental fluctuation will alter the selection environment such that it favors one or more of the inferior alleles.If evolution were allowed to proceed to its stable, climax equilibrium point, then we might experience what you suggest. However, the environment is very complex, very dynamic, and very much in flux constantly. As such, we should expect there to be cycles, balancing acts and fluctuations in the success of the champion allele in conquering its rivals.-----I hope this is helpful to you, Faith. Anyway, have fun debating, and I look forward to other discussions and debates with you in the future.Edited by Bluejay, : Small addition.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith.Thanks for your response. Yeah, that’s right: a trait is fixed when everyone in the population has it, and nobody has something different. For a trait that is decided by one gene, this basically means that there is only one allele for that gene in the entire population.----- I’m not sure I understand what the objection is: isn’t this what we should be doing?I think I personally agree with your oversimplified examples within their limited context. In fact, I’m not sure anybody really disagrees that bottlenecks occur and that they can have major impacts on the future genetic diversity of a population, and that they can and do lead to extinctions.It’s just that you’re not restricting yourself to the limited context in which these simple examples are meaningful: you are extrapolating them to a universal context without incorporating the additional variables that are required to develop an accurate picture of the dynamics at this level.You aren’t saying that genetic bottlenecks can lead to extinction: you are saying that they always do. This is the part of your argument that we disagree with, so naturally, this is the part of your argument that we are going to focus on.----- The only way to make a claim about trends is to compare influx to outflux.But, you have repeatedly brushed off any arguments of ours that attempt to incorporate an influx (i.e. mutations), while maintaining that there is a numerical trend based purely on your observation of the outflux. This is an extremely major inconsistency on your part.Evolution is not only about outflux (elmination of alleles through selection): evolution can only be maintained on the larger scales you’re trying to discuss if it also has influx (mutations). And, there is ample evidence that this influx does occur.For example, here is a paper that used whole-genome sequencing for all individuals of a single nuclear family to estimate the human mutation rate at approximately 60 mutations/individual. If we assume this rate of mutation in some hypothetical population of organisms, natural selection has to whack 60 already-existent mutations from that population every time a new individual is born into that population; otherwise, genetic diversity inexorably increases. That means every new individual born into the population has to die in order to prevent genetic diversity on the scale of the entire genome from increasing!So, even as one allele goes about squelching all of its rivals, genetic diversity at other locations in the genome will be increasing at a very high rate! So, your argument about the dynamics at one locus on the genome cannot really be meaningfully applied to the larger scale considerations of whole-genome and whole-population dynamics. As was pointed out earlier, your extrapolation is a composition fallacy.-----Please, I honestly don’t understand why you are objecting to the tactics we’re using. It seems like our arguments, backed with evidence from actual research and observation, are sufficient to overcome the problem you raise in this thread: doesn’t this mean that we are doing exactly what is required of us to win this debate?Edited by Bluejay, : reworded the part about assuming the mutation rate in the hypothetical populationEdited by Bluejay, : their/there... ughEdited by Bluejay, : A couple rewordings and additions for clarification

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith.Like NWR, I refrained from responding to avoid overloading you. But, since you seem to be taking a poll of sorts, I suppose it would be more beneficial if I filled out the form and sent it in. Like everyone else, I disagree with the get part here. My experience is in chicken breeding, but the principle is the same: a breed is defined by a key set of characteristics, and any animal that resembles these characteristics closely enough can be considered part of the breed (for the purposes of judging at fair competitions or selling commercially), even if most of the genotype of an individual animal actually comes from outside the breed (which it very often does in the case of chickens).However, I do more or less agree with the maintain part.----- I don’t know that I would word it that way (I think NWR worded it more accurately), but the basic idea is close enough to correct that I won’t spend any more time clarifying it. Just remember that selection (of any kind) doesn't act on the population, but on the individual, so it's inappropriate to cite "for the good of the group" as the underlying cause of evolution.----- This is a given, since genetic diversity is proportional to the number of individuals in a population (because of mutation), and a population (or pure breed, in this case) of dogs obviously has fewer individuals than the sum of individuals in all dog breeds together.The trouble is that, in reality, purebreds are extremely rare (rarer than vendors would have us believe). Breeds are not really defined by genotype, but by phenotype (and usually only by a specific set of phenotypic characters, rather than by the entire phenotype), so, like Paul said, we don’t really know how the genetic diversity is distributed among and within different breeds, or how the lack of allelic diversity for breed-defining genes correlates with allelic diversity for genes that do not define the breed.----- No. I disagree with the second part of this question (the first part is pretty much a crap shoot, too). A breed is not defined by genotype, so, as long as the increased genetic diversity does not affect the subset of phenotypic characters that define the breed, the breed will not be considered to have lost its character.----- The basis of natural selection was not for Darwin to decide: he only discovered it; he did not invent it.His understanding of natural selection was very likely influenced by his understanding of domestic selection (I haven’t looked into it in that much detail, though), but my reading of his work indicates that he recognized that there were some important distinctions, such as the lack of directional guidance by an intelligent overseer in the case of natural selection.But, like Dr Adequate wrote, what we currently understand about natural selection is not constrained in any fashion by what may or may not have been Darwin’s primary influences while formulating the rudiments of modern evolutionary thought. Natural selection is not an idea that Darwin came up with: it is a real, observed process that Darwin was trying to describe, and that we, today, understand more completely and more accurately than he did in his day.----- Even before the others responded, I was mentally answering this one with the steering wheel point that the others have used.I maintain that mutation---which I use loosely to refer to all forms of alterations to the genome that result in new alleles or nucleotide sequences---is the ultimate source of all genetic diversity. This, in my mind, is what makes mutation, and not natural selection, the engine of evolution. Because natural selection is the closest equivalent to a guiding hand in evolution, it is more appropriately analogized as the steering wheel or rudder than the engine.----- The second part is correct: evolution is simply any change at all, whether or not it leads to speciation. Like everyone else, I object to the goal imagery, but I’ll spare you another lecture (you apparently realize the inappropriateness of the term anyway): I mention it here only for the sake of clarity.There are many aspects of the evolutionary worldview that should be thought of as the historical events, rather than the integral principles, of evolution. Natural history is a term used to describe the sequence of biological events that occur on Earth, extending well before the point when human history first began: it incorporates all of the historical components of evolution. Speciation is a process that is seen in the fossil record and the genetic evidence, and is thus appropriately seen as a part of natural history. Evolution, however, is the mechanism(s) behind the historical events and the theoretical principles used to describe the mechanism(s). Evolution can still occur in the absence of speciation.In this debate, we are in the habit of referring to the Theory of Evolution, its mechanisms, its processes, and it outcomes, as one collective body of information that comprises one side of the debate (the evolution side). Speciation is certainly an integral requirement for our side of the debate, and if you defeat speciation, you will have dealt an insurmountable blow to our side of the debate; however, it needs to be made clear that speciation is not a principle of evolution, but a predicted outcome of it (one of many).Remember also that speciation is as terminologically intractable as species is. In fact, an evolutionary event can only be assessed as speciation ex post facto: it would simply be considered a quantity of accumulated divergence between groups of organisms that resulted in drastically reduced rates of genetic intermixing. The thresholds of divergence and hybridization that define when speciation has occurred can only be determined heuristically, so it isn’t really a concrete, well-defined phenomenon.-----Again, sorry for the length and the detail, but I wanted to be thorough. And, there is much more that I wanted to include here, but I’ll forebear: there’s enough for you to digest already. I hope you take the time to consider all my points, because I honestly think that a simple analysis of what I (and others) have provided here should be sufficient to show that the problems you raised here are not insurmountable to the Theory of Evolution.Edited by Bluejay, : "that equivalent" changed to "the equivalent" and "than the engine" added at the end of the that sentence.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith.If you're feeling overwhelmed, I would be happy to do a Great Debate with you. I usually won't post more than once a day (sometimes less when I have a lot of work to do around the lab), so you shouldn't get overwhelmed with responses.I also like to think I can be reasonable, friendly and patient enough to not get out of line; and knowledgeable enough to understand what you're talking about in population ecology and evolutionary biology.Let me know.Edited by Bluejay, : Subtitle

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Since we're providing commentary, I thought it would be helpful to add some of my own.I honestly don't have a problem with Faith. I agree that she doesn't know enough about genetics to support her grandiose claims, and that her arguments suffer from this, but her perspective on the issue seems perfectly reasonable to me, given her background.From the outside, science certainly does look like a bunch of people applying a certain ideology to some data, and teaming up to keep all other ideologies out. From the inside, it sometimes looks to me like a bunch of passive-aggressive elitists who are more concerned with their reputation within the community than with the actual pursuit of knowledge. So, I sympathize with Faith for that.I don't see how insults and mockery are going to help change her perspectives or opinions about us or our work. If we were actually debating in formal forum, like a journal editorial section, it would probably be appropriate to do our utmost to ensure that people with stupid ideas were made to like look idiots and replaced with people who are more useful and productive. But, in an informal debate like this, I agree with CosmicChimp that the most important thing is to garner understanding.Otherwise, we'll just end up with only evolutionists talking amongst ourselves about how stupid creationists are. And that's extremely boring.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Dr A. She seems to have done at least some study of it, from what I can tell. Probably not as much as she thinks she has, sure, but I don't think it's fair to expect her to shut up until she has fulfilled all of our requirements.Let's face it, a general fact of science is that none of us actually knows as much as we should or could about the things we study. That's the reason we study them. And, my experience so far has been that making stupid arguments to people who know better while not realizing how stupid your arguments really are is an expected part of graduate education in the biological sciences. As far as I'm concerned, it should be an expected part of this debate, as well.Other than annoying the crap out of you (which really isn't that much of an accomplishment, by the way), she hasn't really done any harm. She seems intelligent enough to be worth the effort, and she's actually made some good insights insofar as her initial assumptions allow.I'm optimistic about the Great Debate topic. I doubt I'll ever convince her that evolution is correct, but I think I've already made a little progress toward helping her understand where the arguments come from and why they make sense.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith. Faith, you're not helping yourself here. Nothing that has been said by evolutionists on this thread can realistically be interpreted to mean they think speciation is not needed. Comments like this make everybody think you aren't taking the time necessary to assimilate what you read.I think it would be in everybody's best interest for you to ignore what people are saying on this thread and focus on our Great Debate thread.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Pluto. I think you're going to need to explain this a little better.Are you saying that the ability of a diverse assemblage of dog varieties to interbreed can somehow be used as support for Faith's idea that all that genetic diversity was present in the original gene pool of dogs/wolves?

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Wounded King. My take on this is that, while neo-darwinists’ using the term didn't cause Faith's lack of understanding, it hasn't helped. Her main problem in her debate with me was not being able to understand that the term beneficial mutation doesn’t refer to a beneficial mutation, per se, but to a mutation that causes a beneficial phenotype. She honestly thinks that there is a meaningful difference between beneficial and deleterious mutations, as if they arise from two different kinds of processes, even though this is very similar to categorizing automobiles by their colors, rather than by their class or manufacturer.This led her to think it was perfectly reasonable to demand separate evidence for deleterious and beneficial mutations, and then for separate evidence for beneficial mutations in different kinds of organisms. My showing her an example of the same kind of mutation (an A -> G substitution) leading to both beneficial and deleterious effects on phenotype apparently failed to convince her: as I feared, the combination of seeing an undeniable beneficial mutation and not understanding that benefit is irrelevant to the occurrence of mutation led her off on some insane story about how bacteria have a special means of changing their genomes, rather than to take it as evidence that beneficial and deleterious mutations are, in fact, not different things, but the same thing with different consequences.While I don't object to the usage of the term "beneficial mutation," I think it should be used cautiously until someone can get the idea that "beneficial" is not a mechanistic category to penetrate Faith’s skull.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Wounded King. Well, she did acknowledge that at least one of the mutations I presented did have a beneficial effect on the bacterium's phenotype. Of course, she found another philosophical viewpoint to preserve her original argument (at least in semantic form), which is a product of a larger issue than her denial of beneficial mutations.I realize that I made no ground in convincing her of the importance and logical power of scientific theories. Like so many creationists, she has concluded that the "ideal" version of science is a simple fact-gathering enterprise with no thinking involved beyond the planning needed to design experiments for the collection of data.As long as she holds to this opinion and refuses to accept that theories are not endpoints--but also sources---of knowledge, getting her to acknowledge one or two of our factoids is a only pyrrhic victory.I think you're right: her issues are deeper than just this specific argument.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith.I had sworn off debating with you on this topic, but I've got to put one little tidbit out here for you to see: If such mutations could stay in the population, what is to stop it from being one of the alleles that comes to dominate a daughter population, thereby distinguishing the daughter population from the parent population?Wouldn't this be the addition of a new allele, which then came to dominate a population? And, wouldn't it be working according to the basic process you described in your argument?This is what we are talking about: this is how evolution happens, and this is how mutation changes the entire countenance of your model.Edited by Bluejay, : "your" to "you"

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith. But, they all suffer from the same genetic bottleneck problem, don't they?

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, Faith. This has been addressed multiple times already, you just haven’t recognized it as such.When I try to visualize your argument, I think of the old Atari game Asteroids (yes, I am old enough to have played it*). *...if by it, you mean the version that was remade for Windows in the early 1990’s).Have you played that game? When you shoot an asteroid, it breaks into two or more smaller pieces. Then, if you shoot the pieces, they break into two or more even smaller pieces. It continues like this until the asteroid pieces are so small that the next shot disintegrates them.This is very much analogous to your argument, if we think of the size of the asteroids as representing the genetic diversity of distinct populations. When an asteroid (population) is broken into two pieces, the two pieces are smaller (less diverse) than the original asteroid (population). With enough shots, the player can destroy all asteroids on the screen (drive all populations to extinction). This is akin to the process of evolution as you see it happening: reduction by fragmentation until there is nothing left.What this model does not incorporate is the opposite effect. Like you say, IF mutations can create new variations in the population, genetic diversity in the population increases as mutations happen (your words were, ...tends to [make] a mixed multitude of the same species...).An analogy for the game Asteroids would be a game mechanic that allows the asteroids to grow in size over time. Think of the consequences of this: you could shoot an asteroid, breaking it into smaller pieces, and the pieces could subsequently grow until they were as large or larger than the original asteroid. If a player is a poor shot, the asteroids’ growth could easily outpace the player’s ability to break them up, and the player would never be able to clear the screen of asteroids. In fact, the player may end up with many more---and much bigger---asteroids then he started with!This is what we hypothesize about evolution (in a very simple, abstract way): genetic diversity can accumulate before, during and after speciation, because of the inevitable process of mutation. Regardless of what causes speciation/isolation, mutation will happen, and can, in fact, counteract the negative effects of natural selection and genetic drift on diversity.Thus, populations are not necessarily doomed to wallow in shallow gene pools forever: if they can survive genetic bottlenecks, and if new mutations can add genetic diversity, there remains no reason to think they cannot evolve.This is what evolution is all about: mutation to produce more product, and selection to pare it down by functionality. It is fundamentally a question of the rate of accumulation of new alleles versus the rate of extremination of old alleles.Edited by Bluejay, : Small addition.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.